Welded spigot and socket joint



July 28, 1931. J, GRADL 1,816,770

WELDED SPIGOT AND SOCKET JOINT Filed May 24, 1926 Fig.1 I

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Patented July 28, 1931 UNITED STATES PATENT; OFFICE JOSEF GBADL, F HUCKINGEN-ON-THE-BHINE, GERMANY, ABSIGNOB TO THE IIBI MANNESMANNROHREX-WERKE, 0F DUBSELDORF, GERMANY WELDED SPIGbT AND SOCKET JOINT A Application filed May-24, 1926,- Serial No. 111,451, and in Germany Kay 27, 1825.

joints of a known kind for pipes the socket was sealed with lead wool, tarred hemp rope and the like. Such joints took a considerable time to make and In spigot and socket frequently became leaky, a circumstance which caused great losses. in the case of gas mains. For this reason in place of these spigot and socket joints pipes have been butt- Welded together. Welded spigot and socket joints have also been used to some extent. In the case of smooth pipes grooves have been impressed in the wall of the pipe close to the weld, to allow for the strains due to shrinkage in the material. It has been found that with welded spigot and socket joints,-considerable bending stresses occur which endanger the weld and are a frequent cause of broken connections and leakages. in making the welded joint, the protective layer usually provided on the ipes is destroyed round about the place 0 junction, it has been found that considerable corrosion through rust and the like results. I

The drawbacks of the known welded spigot and socket joints are overcome by the present invention, through the socket being provided with a corrugation or double ange as a means compensating for the strains caused by URI internal sockets.

In welded sockets of a known kind it has ge otecting means being introduced into the lloW space formed by the corrugation and e like.

Since, f

according to the load after the joint The invention is illustrated in the accompanying drawings, wherein- Figure 1 is a longitiudinal section of part of a welded joint according to the invention,

Fig. 2 is ,a similar view of a slightly dif- 5-5 ferent typeof joint, and

Fig. 3 is a similar view of still another form of the invention.

Refering now particularly to Figure 1, the following will be seen:

he socket a is provided with a corrugation The weld is made at c. The weld may be an autogenous or an electric one. In order to protect the weld from being subjected to ending stresses,'the smooth end d of the in-' serted pipe is introduced into the socket a and caused to bear closely at the places e and The lap 9 may be made any suitable depth on the line of piping. In the cases of pipes which are not highly stressed and are well supportedthe lap need be no deeper than the corrugation as shown in Fig. 2. In making the joint, the pipe end 03 which is bevelled off to fit the heated and then bent to the pipe. when cooling rugation b.

In order to eliminate the danger of rusting due to the burning away of the coating of anti-rust composition, the pipe end (I is pro vided with one or more holes it, in order that has been made the hollow space by having asphalt or cement sprayed or pressed into it. Similar holes may also be provided as indicated in the socket or its corrugation. After the asphalt or cement has been introduced, the holes may be closed again by means of screws. The holes 71. really constitute normally closed ports for they are opened only to permit filling o the hollow space 2' with anti-rust composition, and are immediately closed thereafter. Fig. 3 shows a similar arrangement for an internal socket. The end of the inserted pipe provided with the corrugation b is lightly driven into the slightly flared socket 70' so as to bear at Z. Thereupon the end of the down and welded at c Any strains due to shrinkage are readily taken up by the cor- 80 corru ation is welded autogenously or electrical y' to the socket. In this case as well the corrugation b will take up the strains due to shrinkage. To allow for the pipes not being truly round, the end of the socket is flared at m. In order. that the cross-section of the pipes shall not be reduced at any point, the two pipe-ends'may be expanded. Holes h for introducing an anti-rust agent may be lo provided in thiscase as well.-

I claim:

A pipe joint comprising a socket, a spigot adapted to be introduced into said socket, said spigot contacting the wall of the socket m at the outer end of the socket and at a point remote from the end of said socket, and a weld uniting said socket end and said spigot, the socket being corrugated between the points of contact to form a-hollow space between said in socket and spigot, said corrugation being adapted to act as an equalizing means for taking up the strain caused by the welding operation.

In testimony whereof .I have signed my 35 name to this specification.

J OSEF GRADL 

